Wrap-around carriers are quite often used to package beverage bottles. This is commonly carried out by positioning a carrier blank on the tops of the bottles to be packaged, folding the sides of the blank down and forming a bottom panel from flaps extending from the side panels. The bottles typically are carried through a packaging machine by transporting means which provides space for folding the flaps and for connecting mechanical locking elements on one flap with corresponding openings in another flap. In the type of carrier under discussion openings are provided in the top panel to receive the necks of bottles contained in the carrier.
A problem encountered in the use of wrap-around carriers to package bottles is the fact that bottles which are of the same nominal size are not always the same actual size. Thus the wrapper of a package containing relatively large size bottles would normally fit very tightly about the bottles compared to the wrapper of a package containing relatively small size bottles. This condition has been alleviated by using carrier blanks provided with two different sets of mechanical locks, one set of which is actuated when the perimeter of the package is relatively large, due to the presence of oversized bottles, and the other set of which is actuated when the perimeter of the package is relatively small, due to the presence of undersized bottles. The locks have typically been located on bottom panel flaps used to form the bottom panel of the carrier. Examples of such carriers may be found in U.S. Pat. No. 3,548,566, issued on Dec. 22, 1970 to Earle C. Sherman, and U.S. Pat. No. 4,437,606, issued on Mar. 20, 1984 to Earl J. Graser.
While these measures were effective in providing for a tight package of bottles which could vary in size within relatively small predetermined limits, it has been found that bottles used today tend to vary in size more than they previously did, making it more difficult to compensate for size differences by the different sets of mechanical locks discussed above. This appears to be the result of high volume bottle forming operations which have reduced the lifetime of the bottle molds. It is now necessary to clean and polish the molds more often. Since the polishing operation is abrasive, it reduces the wall thickness of the molds each time it is carried out, resulting in larger molds which produce larger size bottles.
To redesign the carrier locking means to accommodate these larger variations in bottle size would require the carrier locking panels to be made larger, which is undesirable from a cost standpoint. It would be highly desirable, therefore, to be able to provide a tight wrap-around carrier which compensates for large variations in bottle size without resulting in costly design changes to either the carrier itself or the packaging machine.